Gear checking apparatus



May 15, 1962 Filed June 6, 1955 r' I I. .I

B. F. BREGI GEAR CHECKNG APPARATUS 2 Sheets-Sheet 1 TYPICAL CHART INTERPRETATION S PERFECT TOOTH LEAD SPACING B: THICKNESS CORRECT CORRECT LEAD Bl THICKNESS SPACING ERROR..OOOI

THIN TOOTH LEFT SIDE `OOOl THIN THIN TOOTH BOTH SIDES .OOOITHIN THICK TOOTH BOTH SIDES TOOTH OFF ANGLE.OOO2

TAPERED TOOTH \OOO2 THICK AT CENTER CENTER CROWNED TOOTH .0002 THICK AT CENTER HOLLOW TOOTH .0002 HOLLOW AT CENTER EACH SIDE FIG.I.

INVENTOR.

BENJAMIN F. BREGI ATTO EYS May 15, 1962 B. F. BREGI 3,034,219

GEAR CHECKING APPARATUS Filed June 6, 1955 2 Sheecsz-Sheell 2 IN VEN TOR.

United States Patent C) 3,034,219 GEAR CIECKDIG APPARATUS Benjamin F. Bregi, Grosse Pointe Park, Mich., assigner to National Breach & Machine Company, Detroit, Mich., a corporation of Michigan Filed June 6, 19,55, Ser. No. 513,433 3 Claims. (Cl. 32a-179.5)

The present invention relates to gear checking apparatus, and more particularly, to an instrument designed to automatically check each tooth of a gear from end-to-end and .to record the results of such tooth check on a chart.

It is an object of the present invention to provide a fully automatic gear checking apparatus designed after placement of a gear thereon to effect a sequential check of each tooth of the gear, to produce a chart showing the results of such checking, and to terminate its operation automatically upon completion of the check ofthe tooth.

It is a further object of the present invention to provide gear checking 'apparatus to effect a simultaneous checking of opposite sides of a single gear tooth `and -to carry out such check sequentially upon all teeth of a gear.

It is a further object of the present invention to provide a gear checking instrument designed to check 'both sides of each tooth of a gear land to produce a chart showing the results of such check, the chart indicating tooth thickness, tooth spacing both tooth-to-tooth and cumulative tooth spacing, tooth angle, tapered teeth, crowned teeth, and hollow teeth.

More specifically, it is an object of the present invention to provide a gear checking instrument comprising a support for a work gear, 'a checking device including a pair of relatively movable elements engageable simultaneously with opposite sides of the same tooth of the gear, means for effecting relative reciprocation between the gear support and the checking device, and means for effecting relative indexing motion between the gear and device between gauging strokes.

itis a further object of the present invention to provide a gear checking instrument as described in the preceding paragraph in which means are provided for effecting relative movement between the gear and device in a direction radial of the gear to provide for relative traverse between the device and gear in one direction without effecting a gauging operation.

it is a further object of the present invention to provide an instrument as described in the preceding paragraphs in combination with automatic recording means.

It is a further object of the present invention to provide a gear gauging instrument including means for effecting relative reciprocation in la gauging and idle stroke between ya gear and gauging device, and means for advancing a record chart beneath a recording device in timed relation to relative reciprocation between the gear and device during the gauging stroke only.

It is a further object of the present invention to profvide an automatic recording gauge comprising means for effecting relative reciprocation between a gear support and gauging device, 'and means directly responsive to such relative reciprocation for feeding the record chart so that the record on the chart bears a definite relationship to the dimension along the gear teeth in which the `checking operation ltakes place.

it is a further object of the present invention to provide a gear checking instrument designed to effect rapid and accurate checking of both sides of all of the teeth of a gear, either helical or spur, and to produce an accurate record chart of the results of the checking operation.

Other objects and features of the invention will become apparent as the description proceeds, especially when 3,634,2l9 Patented May l5, 1962 taken in conjunction with the accompanying drawings, wherein:

F iGURE l is a view of la typical chart showing different results recorded as ia result of the checking operation oi the instrument disclosed herein.

FIGURE 2 is a perspective view with parts broken away of the complete gear checking instrument,

FIGURE 3 is a fragmentary perspective view of structure added to the instrument shown in FIGURE 2 adapting it to the checking of helical gears.

Referring now to FGURE 1 there is illustrated the chart it) having thereon typical representations of the record made by the operation of the present gear checking instrument, together with labels indicating the gear characteristic shown by the chart of the several teeth.

Referring now to FIGURE 2, the gear checking instrument comprising a main base 20 which may be a casting or which may be fabricated `as desired. The base 2t) includes Ian upstanding housing portion 22 in which the drive motor, drive mechanism, and indexing mechanism is received. The base 20 comprises a bed portion provided as illustrated with an inclined seat 23 adapted to receive longitudinally extending bearing means indicated generally at 24 for a longitudinally movable main slide 25. At its top the slide 25 is provided with a longitudinally eX- tending T-slot 26 in which is adjustably received intermediate slide 28. The intermediate slide 28 is provided with la transversely extending grooved seat 30 in which is supported a transverse slide 32. Carried by the transverse or cross slide -32 lis a checking device indicated generally at 34 which will subsequently be described in detail.

Located within the housing portion 22 of the base 20 is a motor 36 having a worm 3S connected to its drive shaft and meshing with a worm gear 40 secured to the main drive shaft 42. The main drive shaft 42 has thereon a gear 44 meshing with a second gear 46 carried by a shaft 48 extending at right angles to the main drive shaft 42. The shaft 48 carries a variable stroke crank 50 having a groove 52 in which the driving element 54 of the crank is longitudinally adjustable to vary the stroke. Pivoted to the base at 56 is a lever 58 having a slot 6G in which the element 54 is longitudinally reciprocable. Pivoted intermediate the ends of the lever S6 is a link or connecting rod 62 which is pivotally connected to the main slide 25 as indicated at 64. From the foregoing it will be observed that the main slide 25 is reciprocated ba'ck and forth in a complete forward and return stroke once during each rotation of the crank. The right angled drive gears 44 and 46 are of equal size and accordingly the main slide 25 makes a complete reciprocation once during each rotation of the main drive shaft 42.

' The portion of the main -drive shaft 42 which extends within the hollow interior of the main slide 2S is -splined as indicated at l66. Extending into the interior of the main slide 25 and tixedly secured to the intermediate slide 28- is a cam support 68 to which is journaled the cross slide cam 70, this cam being splined to the spline portion 65 of the main drive shaft 42. The `cross 'slide 32 is provided vvith a depending portion 72 carrying =a threaded cam abutment screw 74 the inner end of which engages the surface of the cam 76x Suitable spring means indicated diagrammatical-ly at 76 bias the cross slide 32 in such a direction las to maintain the end of the cam abutment position. Thereafter, depending on operation of the instrument, the cross slide 32 is cammed radially of the shaft of the gear being gauged in a cycle completed once during eachrevolution of the main drive shaft 42. Thus, in the normal operation of the instrument, the cross slide 32 may remain in gauging position during a working stroke of the instrument and may then be cammed radially `away from the gear to provide an idlestroke in which the sensing elements of the' gauging device do not VContact the teeth of the Work gear.

The Work gear indicated Vat G is shown as supported on a stub arbor 8d and may conveniently be retained thereon by a loclr nut 32 of the quarter turn type engaged on the threaded end S4 of 4the arbor. The arbor is rigidly secured to the work spindle 86 which is rotatably received Within quill 8S which is ixedly received within a tubular projection 9G of the housing or Vheadstock portion 22 of the base. lf desired, Vand as dictated by the particular gear being checked, va talstock 92 is provided which may in turn carry a live center for engagement with a gear or gear'supp'or'ting fixture. The tailstock 92 is longitudinally adjustable along Vways 94 provided on the bed of the bese .and may be clamped in operating position. Center 95 may be operated through a lever 9.6.

In order to effect indexing of the Work gear once during each complete forward and reverse stroke of the gauging device, the quill 88 is provided with an annular groove 98 in which is rotatably received a circular part 100 of aV movable support element 101. The spindle 86 has rigidly securedl to its inner end an index plate 102 provided with accurately formed index notches 104. The quill 88 includes a radially extending ange 166 located within the headstock. portion of the .casting and pivoted to the flange 166 as indi-cated at 108 is onelink 110 of la toggle device, the other link of which is indicated at 112. Link 112 is Y pivoted fas indicated at 114 to an yarm 116 extending radially from the-circular'p-art 160 of themovable support element 161. The inner ends of the toggle links `and 112 are pivotallyfconnected by a pivotY pin 118, which pin carries a roller 126. A tension spring indicated gener-ally at 122 is provided tending'to cause the axes of pivot connections 108 land 114 yto approach. r

Pivoted to the arm 116 is a feeding pawl 124 having aV spring 126'urging the pawl into engagement with the pe.- ripheral surface of the index plate 162. Pivoted to the flange 106 of the quill'SS is a locking or locating pavv'l 12S having a. portion adapted to fitisnugly 'withina recess in the Y index plate and so to locate the Work spindle in accurately indexed position. Y

VThis indexing V'mechanism is operable by `an actuating lever 130 which is pivoted as indicated at 131 to suitable means on the main base. Rigidlyconnected to the drivev Vshaft 421s an indexing cam 132 the periphery of which is concentric vvith'` the axis of the work spindle 86 and has an angular extent suliicient to remainrin engagement with the roller 120 during the angular movement of the parts necessitatedk when checking ahelioal gear. l

' friction roller 172 xedly secured thereto.

It is suiiicientV Vto* noteVfor the time being, that the arcuate surface 1314!-V Y vdirection.

1 Theindexing operation is carried out once duiingeach Q,

:rotation of the main drive shaft 42. Movement of the lever 139 in a `clockwise direction straightens out the toggle comprisingl links 11tlarndv112 and thus rocks the support..

p element 1t1about-tl1e axis of theivvork spindle. Vlvfl'otiou f y e is transmitted to the'workjspindle through the feed pawlV 124and the index plate. ;.`Thismovement results in forcing Vthe locking and locatingpawl 12S-out of .a recess of the index plate. Suitable spring means'are of course provided recess and the feed pawl rides out of la notch and moves over the peripheral surlface of the index plate into the next succeeding notch.

Means are provided for locating the gear G accurately with reference tothe index plate 162 when it is lirst mounted on the instrument. To accomplish this a locating tooth 14d is provided on a slide 142 movable in a direction perpendicular to the axis of the gear G on a block 1154 which is adjustable along the T-slot 94 previously referred to. The tooth 14% is adapted to fit within a tooth space on the gear G and to hold the gear in proper angular relationship while the nut 82 is tightened, Spring means indicated at bias the slide'142 radially outwardly on the block 144 with respect to the gear G. Manually operated means` are provided for moving the slide 142 toward the gear and comprise an operating lever 143 extending to the front of the machine and adapted to be depressed to rotate a shaft 15?: carrying a second lever 152 the end of which is engsgeable with the slide 142. With this construction the operator is required to'depress the lever 143 and to hold it depressed while locking the work gear G in posi-tion. Upon release of the lever, the spring 146 retracts the tooth 140 from the work gear. Preferably, a suitable limit switch actuated by retraction of the slide 142 is also provided to prevent initiation of automatic operation of the instrument unless the slide is retracted to a position'in which the tooth- 14() will not interfere with indexing rotation of the gear G.

in order to provide la record chart which shows the true condition of the gear with respect to its characteristics as determined by the present instrument, suitable recording means are provided. The recording means comprises means for advancing the chart 10 in timed relation t0 advance of the gauging device in its gauging stroke. nasmuch as the reciproca-ting movement of the main slide 25 is the result of crank action, `it Will be apparent that the velocity of the slide is non-uniform. In order that the charted representation of the gear tooth shall be compar-V able poirit by point to longitudinally spaced points on the-gear tooth, it is essential that the chart be advanced in definitely timed relation to the movement of the gauging device. This is accomplished in the presenty instance by advancingvthe elongated tape-like chart by one or more feeding rolls 169 carried by a shaft 162 and driven through gears 164,7'166and 16d from ,a shaft 169. The shaft 169 is coupled to a drive shaft 170 by a one-way clutch device 171. The Vshaft l17) has -rigidlysecured thereto a Over the friction roller 172 isa friction tape 174, one end of which is fixed to the main slide as indicatedrat 176.Y The other end of the tape is tixedly secured to the base of the machine by a bracket indicated Vat 1,78, the tape forming a bight or loop ld in which isY received aV roller 182 connecte' to abracket 184 from which is suspended a counter- Weight 136. With this arrangement forward movement of the slide A2,5 on a gauging stroke draws the friction tape 174 over the roller 172, turning the Vshaft 17d and the driving element of the one-way clutch 171 in a clockwise This rotationV of the shaft 174i is thus transmitted directly to the Vshaft 169 Yandrhence results in aV Vl he gauging device indicated'generallyat 34 comprises VVapair of sensing elements or lingers 19d and 192 which l are pivoted on axes determined" by pivot pins 194 for -for biasing'the'locking .paWl 128Ay intocontact with the pe "ripheralfsurfaceof the index plate. As'the lever 130 is Y `all'osved'to .in acouriterclockwise direction, Vthe Vlocli- Y ingor locating pawl 128 drops into theY appropriate index:

recitingV movem nt as theftipsfof these fingers yare moved longitudinally of the teeth ofthe gear G. The rear ends of the lingers 194.9 arelassociated with core elements movable longitudinally of windings of Vlineal transformers indicated d*ilammmaticallyVV at 196. Lineal transformers used as sensitivemeasuring elementsV are Well known-"and operate to varycurrent in an electric control circuit. lnV

the present instance, variations in current in the windings of the lineal transformers are caused to actuate indicating needles 19S movable over dials indicated at 200, and also to actuate recording pens or needles 202 movable over the advancing elongated char-t 10.

From the foregoing it will be observed that so long as the motor 36 is energized, the slide 2S will reciprocate back and forth and once during each reciprocation the gear G will be indexed one tooth space. At the same time, during each forward stroke of the gauging device 34, the recording chart will be advanced proportionately to the advance of the slide and a permanent record produced on the chart by the movement of the pens 202 in accordance with movement of the sensing fingers 190. The motor 36 thus mechanically effects reciprocation of the slide 25 and by cam means effects movement of the gauging device into and out of operating position and indexing of the work spindle while the gauging device is out of contact with the gear. At the same time, movement of the slide is employed as the actuating force for advancing the chart.

In order that the instrument may be fully automatic it is provided with an electrical circuit controlled by start and stop buttons 204 and 206. The circuit is not illustrated herein since it may be conventional except that it includes means responsive to the position of the locating tooth 140 to prevent energization of the motor 36 so long as the linger 190 is engaged in a tooth of the gear G.

Otherwise, the circuit includes a counting device which Y may be manually set to interrupt the circuit after -a predetermined number of strokes of the slide 25. Obviously, the counting device will be set to correspond -to the number of teeth of the gear so that after all teeth have been accurately gauged, the motor 36 stops.

Referring now to FIGURE 3 there is illustrated means for converting the instrument shown in FIGURE 2 for operation in conjunction with helical gears. In this case the quill 88 is rotatable in the headstock. The work spindle 86 is rotatable in the quill. Mounted on the quill is a helical compensating member 210 provided with a helically extending groove 212 thereon corresponding to the helix of the teeth of the gear to be gauged.

Rigidly mounted on the main slide 2S is a bracket 214 having a finger 216 adapted to engage in the helical groove 212. With this arrangment back and forth reciprocation of the main slide 25 results in a corresponding back and forth angular movement of the quill k88.

The indexing structure employed is exactly as illustrated in FIGURE 2. It will be appreciated that with this arrangement angular movement of the quill 88 is transmitted to the index plate 102 through the locking pawl 128. Furthermore, indexing is accomplished by rotation of the movable support element 101. The angular extent of the surface 134 of the index lever 130 permits the indexing operation to take place during the return or idle stroke of the plate even though during such return or idle stroke the quill 8S is being rotated by engagement between the fingers 216 and the helical slot 212.

While the sensing elements or fingers 190 and 192 may be adjustable, it is contemplated that the entire sensing device 34 will be replaceable as a unit and designed for a particular gear G. At the same time, it will be understood that the electrical circuit including the lineal transformer employed as amplifying means for movement of the sensing ingers includes means for effecting adjustments to zero to indicating pointers 198 and the recording pins or needles 202.

The drawings and the foregoing specification constitute a description of the improved gear checking apparatus in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

6 What I claim as my invention is: 1. Fully automatic gear gauging and recording apparatus comprising: a base, a rotary gear support on said base, a gauge support onv said base, gauging means on said gauge support comprising a pair of independently movable sensing elements spaced to engage simultaneously with a pair of oppositely facing tooth surfaces of a gear on said gear support, means mounting said supports on said base for relative movement comprising in sequence a gauging stroke parallel to the axis of said gear support, amovement radially outwardly of said gear support into clearance, an idle return stroke parallel to the axis of said gear support, and a movement radially inwardly of said gear support to locate said sensing elements in position for the next gauging stroke,

means for indexing said gear support during said idle with movement of one of said sensing elements during each gauging stroke in a direction transverse to the direction of tape advance to produce on said tape a series of pairs of generally parallel lines in which corresponding lines of all pairs are in general alignment longitudinally of the tape to provide a visible record as to thickness, taper, lead and form of each gear tooth, and providing for ready comparison of these characteristics throughout the series of teeth.

2. Apparatus as defined in claim 1 which comprises lead bar mechanism connected between said rotary gear support and index means, and said gauge support, to rotate said gear support during gauging and idle return strokes in accordance with the helix angle of a work gear, and means for actuating said index means during the rotation of said gear support during an idle return stroke.

3. Apparatus as dened in claim 1 in which the drive means comprises a cam shaft having cams thereon to operate the index mechanism and provide the relative movement between said supports into and out of clearance, a second shaft and mechanism driven thereby to provide the relative movement between said supports in gauging and idle return strokes, and means for driving said shafts continuously in timed relation throughout the gauging of the predetermined number of teeth of a work gear.

References Cited n the file of this patent UNITED STATES PATENTS 1,254,062 Olson Jan. 22, 1918 1,588,963 Harter June l5, 1926 2,046,506 Drader July 7, 1936 2,108,414 Schurr Feb. 15, 1938 I2,206,852 Poupitch July 2, 1940 2,261,093 Poupitch Oct. 28, 1941 2,563,000 Bean Aug. 7, 1951 2,621,556 Beardsley Dec. 16, 1952 2,640,272 Bean June 2, 1953 2,648,912 Osgood Aug. 18, -3 2,775,041 Pomernacki Dec. 25, 1956 2,807,175 Tandler Sept. 24, 1957 2,846,773 Carlson Aug. 12, 1958 2,914,861 Flair Dec. 1, 1959 FOREIGN PATENTS 379,854 Germany Aug. 30, 1923 715,302 England Sept. 8, 1954 

